High-Arched Athletes Exhibit Significantly Greater Vertical Stiffness Values Than Low-Arched Athletes During A Landing Task

Abstract

High-arched athletes (HA) have been shown to have greater ankle and knee joint stiffness as well as leg stiffness during a running task. However, only a single study has examined the role of foot function in load attenuation during a landing task. Though this study demonstrated that HA compared to LA athletes exhibit unique frontal plane kinetics, the role of sagittal plane stiffness during a landing task remains unclear. PURPOSE: Therefore the purpose of this study was to quantify vertical stiffness in HA compared to LA athletes during a landing task. METHODS: Ten HA and 10 LA female athletes performed five landing trials from a height of 0.3 meters while three-dimensional kinematics and ground reaction forces were collected using an 8-camera motion capture system (240 Hz, ViconPEAK) and a force platform (960 Hz, AMTI), respectively. Vertical stiffness was calculated as the quotient of the peak vertical ground reaction force divided by the vertical displacement of the center of mass (tracked by L5-S1 marker) between initial contact and peak knee flexion. Independent samples t-tests were used to compare peak vertical ground reaction forces and vertical stiffness values for the HA and LA athletes. RESULTS: No differences were observed in peak vertical ground reaction forces (p = 0.780; HA: 2.20 ± 0.12 BW; LA: 2.29 ± 0.07 BW). HA athletes had significantly greater vertical stiffness values than LA athletes during the landing task (p = 0.013; HA: 18.3 ± 8.3; LA: 11.0 ± 3.5). CONCLUSIONS: These findings show that HA athletes. These data suggest that the increased vertical stiffness is likely due to smaller vertical oscillations of the center of mass during the landing phase as no significant differences were observed in peak vertical ground reaction forces. The findings of this study suggest that forces applied to the musculoskeletal system, potentially underlying injury, may be altered through movement retraining.